Automatic control and safety cover for extractors



March 1l, 1952 0, w, JOHNSON 2,588,634

AUTOMATIC CONTROL AND SAFETY COVER FOR EXTRACTORS Filed Aug. 24, 1946 2 SHEETS-SHEET l l. JIHMIHlhl 7a FIG-3 INVENTOR OSCAR W. JOHNSON ATTORNEYS Mawh 11',v 1952 Q W, JOHNSON 2,588,634

AUTOMATIC CONTROL AND SAFETY COVER FOR EXTRACTORS Filed Aug. 2A, 1946 2 SHEETS- SHEET 2 INVENTOR OSCAR W. JOHNSON BY fw ATroRNEYs Patented Mar. l1, 1952 UNITED STAT l-:s PATEN T OFFICE AUTOMATIC CONTROL AND SAFETY COVER FOR. EXTRACTORS i Application August 24, 1946, Serial No. 692,876

This invention relates to centrifugal extractors such as are used for extracting liquid detergent,v

e. g., soap solution or a volatile solvent, from garments or fabrics washed or cleaned in a laundry or dry cleaning plant. The invention has more particular relation to the control mechanism including the safety cover lock.

'i One objectof .the invention is to provide an extractor equipped with an improved pneumatic electric control system, operation of which closes andlocks. the safety cover, starts the driving motor, times the extracting operation, opens the motor'4 circuit at the conclusion of the extracting operation,- applies the brake t bring the basket: to rest, -signals the operator that the extracting operation isnished, and, upon initiation by the operator,` opens the cover to enable the'iextracted load to be withdrawn and replaced by a fresh load. i vAnother object is to provide an improved control4 system in which the cover cannot be opened orraised while the basket is rotating; in which itis impossible to start the motor while the cover -is open orywhile the brake is applied; but inwhich, upon emergency, and before the lapse of the predetermined time period, it is always possible to stop the motor and release the cover. Further objects of the invention in part are obvious and in part will appear more in detail hereinafter.

-In the drawings, Fig., 1 represents,- schematically, -one arrangement of control mechanism embodying the invention, the parts being shown in positions assumed when the-extractor basket sat rest,- with brake applied and cover closed; Fig. 2 a vlongitudinal sectional elevation through'the cover operating servomotor; Fig. 3 -is a detail cross section on the line 3-.3, Fig. 2: v

Fig. 4 is a detail view of the brake operating mechanism, corresponding to Fig. 1, showing the brake applied, but with the basket still in motion; 5 is a similar view, showing the brake partsinther' positionswhen the extractor is running, and also when the basket is at vrest with the brake released and the cover raised; andv Fig." 6 is a longitudinal sectional elevation throughone of the pneumatic control valves.` The' extractor itself forms no part of the invention, except as background for or as a part of,the present safety control system. It therefore may be of any suitable form and used for any desired purpose and has been illustrated conventionally and only to such extent as is" necessary or desirable. It comprises the usual curb I 0,

7 Claims. (Cl. 19g-136) 2 provided wtih a cover II hinged at I2, and in which curb rotates the foraminous basket I3 indicated by the dot-dash lines in Figs. 1, 4 and 5, said basket being mounted upon a shaft I 4 driven by motor I5 `(Fig. 1) and provided with a brake drum I6, with which cooperates a flexible brake band I1.

Brake band I1 has one endconnected at I 8- to a lever I9, pivoted at 20 to a fixed support, and its opposite end provided with the usual abutment 2| through which passes a link 22 on which is an adjustable compression spring 23, the other end of the link being connected to one arm of a bell crank lever 24, pivoted upon lever I9 at 24a, the other arm of which is connected to the piston rod 25 of brake band operating servomotor 26,- also pivoted at 20 on the stationary support. l

Lever I9 is biased toward a stationary supporting bracket 21 by a strong compression spring 28,. as in Fig.` 1, but under certain conditions moves away from said bracket to the. position shown in Fig. 4. vBy such motion, to and fro,ias well as by the motion of bell crank 24 and a roller 29 carried thereby, two electric switches, S1, S2, are actuated, yas' willlater appear.

S3 represents a ynormally open manually 0perable push button switch mounted upon a control panel 33. This also supports a manually adjustable clock operated timing shaft 34 havinga setting knob 35 and time indicating dial 36, the shaft being provided with a cam disc 31, coop-v erating with roller 38 on lever 39, biased by spring 40, for actuating the stem, 4I of, a control shown in Fig. 6,`which illustrates valve 43. uEach valve comprises a casing having a supply connecf tion at 55, an exhaust connection or outlet 5,6, and a discharge connection 56a, the stem carrying an inlet valve member 51 and an exhaust valve member'58 biased toward exhaust position by spring 59.

Mounted to swing with the hinged cover II is an operating lever arm 60 (Fig. 1) having a cam Y portion El which operates a small pivoted lever 62, which in turn actuates a fourth electric switch S4. The free end of lever arm 60 is -pivotally connected to the piston rod 63 of cover operating servomotor 64, pivoted on a xed support at 65. As shown in Fig. 2, the piston 66 of this motor travels in a chamber 61 communicating above the piston, by way of adjustable needle valve 68 and larger check valve 69, with the inlet connection at 10, and having an outlet at 1I. Said chamber, below or on the opposite side of the piston, communicates with another supply connection by way of needle valve 12, and inlet 12a. Here, also, the piston rod is provided with a tapered extension locking head 13 having an annular shoulder 14 cooperating with a latch bolt 15 connected to piston 16 working Vin chamber 11. rlhe bolt is flattened on one side, to provide air channel 18, while its opposite or outer end portion carries retracting spring 13 and an operating head 80 outside of the casing accessible for manual operation.

The operation is as follows:

As will later appear, at the conclusion of each extracting operation, the parts come to rest in the positions shown in Fig. 5. Main switch |03 is open; the cover is open; the brake is released; valve 42 is closed; valve 43 is open; switch S1 is closed; switch S2 is open. The pressure supplied by valve 43 effective through cylinder 64 to cylinder 2 6, maintains the brake released.

Let us assume that all parts are at rest, ready foran extracting operation.

The operator unloads and reloads the basket.

An extracting operation is initiated by manually setting the timing device. The hand is applied to the knob 35, by means of which-shaft 34 is rotated to any desired amount,l as indicated on the dial 36, for the desired period of extraction. The rotation of Vshaft 34 turns lever v39 clockwise in Fig. `1, by causing roller 38 to ride up out of the cam recess in which it is shown seated, to a higher point of the cam, and the oscillation of lever 39, against the bias of its spring 40 elevates thestem and valve members of control valve 42, thereby opening its inlet valve member and closing its exhaust valve member.

Fluid pressure, such as air pressure, iows from a suitable source (not shown), by way of pipe 90, valve 42, and pipe 9|, to the upper portion of chamber 61 of servomotor 64, by pipe |04 to motor 54, and, when piston 66 passes outlet 1|, by 5;

pipe 92 to the chamber of servomOtOr'B- The piston 66 of servomotor 64 moves down to locked position, as shown in Fig. 2. thereby closing the cover and locking it closed. Cover closing motion closes switch S4.

Closing of switch S4 energizes a circuit'as follows:

From L1 by wire82 to the junction 98, through an actuating coil 9,9, wire |00, switch S1 and-wire |0| to the junction 81, and thence back to L3 by wire 88, switch S4 and wire 89 to L3. Energi'vation of coil 99 moves over its armature |02, thereby closing, and maintaining closed, the main contactor switch |03, completing the connection of the leads L1, L2, Lc to motor I5, and energizing said motor. As a result the motor immediately starts to rotate the basket and proceed with'the extracting operation.

Fluid pressure transmitted through conduit 9| in the manner described, is also effective, through pipe |04, in servomotor 54, the rod of which moves the three armed lever 45', 41, 52 against its biasing spring 46, to the position shown in Fig. l, in which it is latched by lever 48. Therefore, in control valve 43 the inlet valve member is closed and the exhaust valve member is open, thus evacuating any pressure from chamber 61 below piston 66.

While the parts are in this position, i. e., when the extractor is running and performing its intended duty, the normally open push button switch VS3, which is in a circuit to be later described in detail, is ineffective, because that circuit includes the now open switch Sz. It is therefore impossible, as will appear, to open the cover of the extractor, by manipulation of switch Ss, *whiley the extractor basket is running.

The extracting operation proceeds until the timing mechanism, by operation of its clock or other device for the purpose, returns to its original position shown in Fig. 1, thereby permitting roller 38 to enter the recess in the cam 31. Such operation of lever 39 moves the valve parts of control `valve 42 to the position shown in Fig. 6, closing the inlet valve and opening the exhaust valve. 'I'his evacuates all pressure from the servomotors 26, 64 and 54.

Spring |06 in servomotor 26 thereupon retracts the piston of that servomotor, moving the parts from the position shown in Fig. 5 first to the posi-- tion shown in Fig. l, and applying the brake. Also, opening of switch S1 deenergizes main contactor coil 99 so that the main motorxswitch |03 opens and the motor is deenergized, the basket gradually coming to rest. With power cut off and the brake applied, the momentum of the basket, effectiveupon the brake, moves lever |9 to the position shown in Fig. 4, swinging it away tothe left from the supporting bracket 21, against the force of biasing spring 28. But switch Sz remains open.

4Thus the signal light 8| remainsl deenergized.

But ultimately. when the basket comes to rest. the reactionary back lash, plus theY force of spring 28, returns the brake arm assembly, including lever I9 and its associated parts, back to the position shown in Fig. 1, so that roller 29 moves finger 93 to such position as to close switch S2. Actually, motion of lever 24 to apply the brake Vand swinging motion of lever I9 to the left occur si multaneously, although described separately above.

Closing of switch S2 completes a circuit as follows:

From L1 by wire 82 to the junction 83, wire 84, lamp 8|, wire 85, switch S2, wire 86, to the junc-y tion 81, wire 88, switch S4, and wire 89 to La. The lamp 8| therefore is lighted and notifies the operator that the extracting operation has been finished and that the basket has come to rest.

Closing of switch Sz also renders effective that part of the circuit which includes push button switch S3 (normally open), as follows: From L1 by wire 82 to the junction 83, thence bywire |01, coil 5|, wire |08, switch S3 (still open) wire |09; ,wire 85, switch Sz and wire 86 to the junction 81, and thence back to L3 by wire 88, switch S4.and wire 89, as before. v

The operator now manually closes switch Ss. thereby energizing coil 5|, which attracts the armature 50 associated with that coil, moving lever 48 in the counterclockwise direction Fig. 1, out of the possible path of movement of lever arm 41. The effect'is to release lever arm 41'f0r return movement by its biasing spring in the counterclockwise direction, the arm 45 of said lever elevating the rod or control valveA 43 and opening its inlet valve and closing its exhaust valve.A

`Fluid pressure now ilows from the pipe 9| through valve 43 and by pipe VI |0 to that part .of

ing abutment 14. As a consequence, the pressure in the lower part-"of chamber 61 now becomes effective, and elevates piston 66, which opens the extractor cover, the motion being somewhat retarded due to the restriction of needle valve 12.

As the cover rises, the cam 6I becomes effective upon lever 62, to depress the same and open switches Si, thus opening the return path of Lc,

by wire 83 from the junction 81, thereby de energizing signal lamp 8l. When piston 66 rises beyond the outlet pipe 1l, pressure again ilows` through conduit 92 to the servomotor 2l,`thereby releasing the brake. The basket load is now removed and is replaced with a. fresh load. The cycle of operations has been completed, and the extractor is readyrfor another operation.

As before stated, when the'extractor is in operation it is impossible to open the cover by actuation of the ordinary means provided for that purpose, to wit, normally open push button switch S3, because that part of the circuit which.'v

includes that switch is ineffective by reason of the fact that switch Sz is open. However, it is possible, even when the extractor is running, to stop it and open the cover. This is done by manually returning the shaft 34 of the timing mechanism to its original or zero position, which produces the ordinary series of stopping operationsV before described, and brings the extractor basket to rest, and closes switch Sz. Push button switch Sa is now eil'ective and can be closed to unlock and open the cover. ,-v

Further, it is impossible to start the motor while the cover is open, because cover switch Si is in the motor starting circuit and is always held open by cam 6I while the cover is open.

Similarly, the motor cannot be started at any time when the brake is applied, because switch Si is also in the motor starting circuit and is always open when the brake is applied.

The protruding stem 80 of latch bolt 15 provides for manual release of the cover in the event of emergency, failure of electric current or the supply of i'luid pressure.

Further advantages of the invention Will be apparent to those skilled in the art. 'v

What I claim is: .Y

1. Apparatus of the character described, comprising a rotatable extracting member, a cover for said member movable to open and closed positions, a, fluid pressure operated servomotor for operating said cover, a locking device operatively associated with said servomotor for releasably locking the same in cover closed position, an operator for releasing said locking device, a timing device, manually operated means operatively associated with said operator and controlled vby said timing device for causing operation of said servomotor and operator to open the cover, and means whereby said manually operated means avis rendered ineffective during the extracting operation.

2. Apparatus of the character described, cornprising a rotatable extracting member, brake means for said member, an electric driving motor for said member having an energizing circuit including a main switch, a fluid pressure servomotor operatively connected to said brake means,

anda .motor control circuit effective uponthe motor and including means for closing and maintaining closed the main switch, said control circuit including switch means actuated by said servomotor and arranged .to open the control circuit when the brake means is applied.

3. Apparatus of the character described, comprising a rotatable extracting member', a movable cover therefor, brake means for said member, an electric driving motor for said member having an energizing'circuit including a main switch, a iiuid pressure servomotor operatively connected to .said brake means, a motor control circuit eiective upon the motor and including means for closing and maintaining closed the main switch, said control ,circuit including switch means actuated by said servomotor and arranged to open the control circuit when the brake means is-applied cover operating means, and means actuated thereby for also opening said control circuit when the cover is open.

4. Apparatus of the character described, comprising a rotatable extracting member, a movable cover therefor, brake means for said member, an electric driving motor for said member having an energizing circuit including a main switch, a fluid pressure servomotor operatively connected to said brake means, a motor control circuit effective upon the motor and including means for closing and maintaining closed the main switch, said control circuit including switch means actuated by said servomotor and arranged to open the control circuit when the brake means is applied, cover operating means, means actuated thereby for also opening said control circuit when the cover is open, and manual means controlling the cover operating means and effective only when the brake means is applied.

5. Apparatus of the character described, comprising a rotatable extracting member, a cover for said member movable to openand closed positions, motor means operatively connected to said cover for opening the same, cover locking means operatively connected to and effective upon the motor means to hold the same in cover closed position, brake means for said member, a timing device, means actuated by said timing device for applying the brake means at the conclusion of the extracting period, a single manually operatable means, operating connections effective simultaneously on said motor means and said cover locking means, and responsive to operation of said single manually operatable means for simultaneously releasing the locking means and cover and energizing the motor means, and 0perating means between said timing device and manually operatable means for rendering the latter ineiective during the extracting operation and eiective when said operation is concluded, the brake is applied, and the extracting member comes to rest.

6. Apparatus of the character described, comprising a rotatable extracting member, operating means therefor, a cover for said member movable to open and closed positions, motor means operatively connected to said cover for opening the same, cover locking means, brake means for said member, a timing device, means operated by said timing device and effective upon said operating means for rendering it effective when the extracting operation is begun and upon said brake means for applying the same at the conclusion of the extracting operation, a. single manually operatable means, operating connections effective simultaneously on said motor :means and said cover locking means, and responsive. to operation of said:single manually operatable means for both releasing the locking means and energizing the motor means, and operating connections between said timing means and manually operatable means for rendering the latter ineffectivey during the extracting operation and effective when said operation is concluded, the brake is applied, and the extracting member comes to rest.

7. Apparatus of the character described, comprising a. rotatable extracting member, a cover forsaid member movable to open and closed positions, a double acting fluid pressure servomotor operatively connectedto said cover, means for supplying iiuid pressure to one end of said servomotor for openingvthe cover and to its other end. for closing the cover and holding it closed, mechanical locking means operatively connected to and effective upon the servomotor for holding the same and the cover in cover closed position, a timing. device, means actuated by said timing device when the extracting operation isooncluded and operatively connected to said fluid pressure supply meansvfor evacuating cover closing-pressure .from the servomotor, and manually operated means, operating connections effective upon said fluid pressure supply means, andresponsive to operation of said manually operated means for both causing cover opening iiuid pressure to be suppliedV to said servomotor and for causing release operation of said mechanical locking means.

OSCAR -W. JOHNSON.

REFERENCES CITED The `following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 671,207 Cowperthwait Apr. 2, 1901 1,531,844 Colclough Mar. 31, 1925 1,989,213 Schenck Jan. 29, 1935 2,174,018 Schaum Sept. 26, 1939 2,254,388 Olcott Sept. 2, 1941 2,261,936 Johnson Nov. 11, 1941 2,325,406 Johnson July 27, 1943 2,342,812 Martinson Feb. 29, 1944 

